A typical cotton harvester includes a plurality of individual harvesting units mounted at a forward end of a mobile main frame. Each harvesting unit has one or more picker rotors, with each picker rotor having several individual rows of continuously rotating, circumferentially spaced cotton picker spindles. As the cotton harvester moves over a field of cotton plants, the rotating picker spindles harvest cotton from the plants. In some instances, the spindles are barbed or otherwise roughened to implement their affinity for cotton fiber.
The addition of moistening fluid to the picker spindles has been found to further increase the picking capacity of the picker spindles. Accordingly, a spindle moistening apparatus having a series of spindle moistening pads is typically arranged relative to the picker rotor. The moistening pads supply a moistening fluid, in one form or another, to each of the picking spindles prior to their entrance into the cotton plants. In a later part of the cotton picking cycle, the crop bearing picker spindles are withdrawn from the plant and carried into doffing relation with a doffer assembly. The addition of moistening fluid to the picker spindles further facilitates doffing of the cotton from the picker spindles.
The doffer assembly includes a plurality of vertically spaced, rotatably driven doffer pads. Each doffer pad is arranged relative to a picker spindle to remove or doff the cotton from the spindles and forcibly direct the cotton rearwardly into a discharge compartment or suction door. Following removal of the cotton, the spindles will again be presented to the spindle moistening apparatus for remoistening preparatory to continuation of the cotton picking cycle.
The rearwardly directed doffed cotton strikes a baffle or rear panel structure provided in the discharge compartment and then falls downwardly toward a discharge opening defined at the lower end of the discharge compartment. A duct extends upwardly from the discharge opening and connects the discharge compartment with a cotton receptacle on the harvester.
A stream of air discharged upwardly into the duct at a location downstream of the discharge opening creates a vacuum at the opening and induces a draft at a lower end of the discharge compartment. The cotton falling towards the opening is drawn therethrough and is directed upwardly into the duct. The cotton is ultimately directed into the cotton receptacle by the air stream.
The above-described cotton harvester has proved satisfactory in the majority of cotton harvesting conditions but has limited performance abilities under certain conditions. When harvesting high yield cotton, the doffer assembly discharges a larger than normal volume of cotton toward the discharge compartment. Most of the doffed cotton discharged from the doffer assembly strikes the rear panel structure in the discharge compartment and gravitationally falls toward the opening in the lower end of the discharge compartment. Some of the doffed cotton, however, rebounds from the rear panel structure and tends to repeat around the doffer assembly.
The rotary motion of the doffer pads throws some of the repeat cotton onto the ground. As will be appreciated, the doffed cotton thrown from the harvester onto the ground is lost and reduces the productivity of the cotton harvester. A large percentage of the repeat cotton, however, is again wrapped about the continuously rotating cotton spindles. Subsequent presentation of those spindles wrapped with repeat cotton to the moistener assembly increases the likelihood of blockage or damage to the moistener pads. Blockage or damage to the moistener pad inhibits adequate moistening of the picker spindles thereby reducing their affinity for cotton during the picking operation.
As will be appreciated by those skilled in the art, performance of a cotton harvester is adversely effected under moist cotton harvesting conditions. Moist cotton tends to wrap tightly upon the picker spindles. Tighter wrapping of the cotton on the picker spindles makes it more difficult to remove the cotton from the picker spindles by the doffer pads. As such, moist cotton also has a tendency to repeat around the doffer assembly and cause the same problems mentioned above.
The induced draft created at lower end of the discharge compartment is not always completely effective to draw doffed cotton from an upper end of the discharge compartment. This problem is furthermore aggravated when harvesting moist cotton. It has been observed that moist cotton has an increased tendency to clump and cause blockage at the upper end of the discharge compartment.
To reduce the cotton repeat problem in certain field conditions, it has been necessary to reduce the ground speed of the cotton harvester. Albeit time consuming, frequent cleanings of the discharge compartment reduces the likelihood of complete blockage in the discharged compartment. Both of these proposed solutions, however, adversely effect productivity of the cotton harvester when time is at a premium.